Folding chair construction



A ril 23, 1963 c. L. BEST ETAL 3,086,813

FOLDING CHAIR CONSTRUCTION Filed Sept. 26, 1961 2 Sheets-Sheet 1 INVENTORS (A muss 4. 3557' a; BY DOA/191D JlMmvsoAl m v 6 J} g V April 23, 1963 c. L. BEST ETAL 3, ,813

FOLDING CHAIR CONSTRUCTION Filed Sept. 26, 1961 2 Sheets-Sheet 2 INVENTORS (l/muss Z. B657 BY DaNfllb I-ZMVNJUAI 54w rww ilnited 3,086,813 FGLDlNG CHAIR CQNS'I'RUCTION Charles L. Best, Water-town, and Donald J. Manson,

l vlinneapelis, Minn, assignors to The J. R. Clark Company, Spring Fark, Minn, a corporation of Minnesota Filed Sept. 26,1961, Ser- No. 140,823 6 Claims. (Cl. 297-58) This invention relates to folding chairs.

An object of the invention is to provide a new and improved folding chair construction in which the chair front leg frame extends upwardly at each side of the seat from a. forward portion of the seat to the back to afford a certain amount of arm support for the user and yet which may be simply and quickly collapsed by applying lifting pressure to the rear edge of the seat.

Another object of the invention is to provide a chair construction embodying four legs which generally diverge in their downward extension from adjacent the four corners of the chair seat to give a high degree of stability and yet which allows ready collapse of the chair into a relatively flat compact unit.

Another object of the invention is to provide a folding chair having pivotally interconnected front and rear leg frames with a new and improved mechanism for mounting a fiat chair seat on the frames for movement of the seat between a horizontal use position and an upright collapsed position as the leg frames are relatively moved about their pivotal interconnection.

The above mentioned and other objects of the invention will be brought to light during the course of the following specification, reference being made to the accompanying drawings, in which- FIG. 1 is a front perspective view of the chair in erect condition.

FIG. 2 is a rear perspective view of the chair in erect condition.

FIG. 3 is a side elevation of the chair in erect condition.

FIG. 4 is a section taken along line 4-4 of FIG. 3 showing a bottom plan view of the seat with the chair in erect condition.

FIG. 5 is a fragmentary perspective view from the side looking upwardly at the linkage connecting the chair seat to the leg frames.

FIG. 6 is a vertical section taken in fore and aft direction through the seat just inside of the right side portion of the tubular seat frame, and showing the chair in partially collapsed condition.

FIG. 7 is a side elevation of the chair in collapsed condition.

FIG. 8 is a rear elevation of the chair in collapsed or folded condition with the upper back portion of the front leg frame partially broken away to show the pivotal connection between the front and rear leg frames.

Referring now more particularly to the drawings reference numerals will be used to denote like parts or structural features in the different views. The three main components are generally designated as the front leg frame 10, the rear leg frame 11, and the seat 12.

Frame 10 is of tubular stock formed in an inverted U- shape with the upper portion thereof formed substantially on the major segment of a circle. More specifically the bight portion 14 at the top of the frame curves into broadly curved upper frame portions 15 at each end with the frame terminating in slightly diverging front legs 16. The side extensions of the frame are connected by a rod 17 just above the legs 16 (FIG. 8). The back leg frame 11 comprises a pair of generally parallel upright legs 18 having their medial portions interconnected by a horizontal cross member 19. A cross bar 20 extends between frame portions 15 below the bight portion 14 and is provided with downwardly opening slots 21 (FIG. 8) and 3,835,813 Patented Apr. 23, 1963 ice the upper ends of legs 18 are flattened to extend through slots 21 and are then bent over as at 22 within member 20 forming a hinge connection between that member and legs 18. All of the legs 16 and 18 are provided with friction caps on their lower ends.

A back plate 23 is suitably secured to the upper portion of frame 10 between the portion 14 and bar 20. This plate 23 is curved in the manner of bar 20 to conform to the back of a person seated in the chair.

Seat 12 comprises an inwardly opening peripheral channel member 26 of generally square design having a flat padded seat section 27 secured thereto as by screw and washer assemblies 28 (FIG. 4). Reinforcement bars 29 having their ends secured in the channel 26 extend fore and aft in parallelism under the section 27.

The mechanism for connecting the seat 12 to the leg frames 10 and 11 will now be described in detail with attention being directed particularly to FIGS. 4 to 7. A pair of short links 30 connect the frame 10 to the seat by having their lower ends journaled on rod 17 and their upper ends coaxially pivoted as at 31 one to each of the bars 29. The pivot axes are parallel and extend horizontally and transversely under the seat 12. As will be noted in FIG. 5, the links 30 extend upwardly and forwardly from rod 17 to pivots 31 when the seat is erected.

A pair of longer rear links 34 connect the frame 11 to the seat by having their lower ends pivoted on the flattened ends of a rod 35 which extends through member 19 and their upper ends coaxially pivoted as at 36 one to each of the bars 29. These pivot axes are parallel to those at 17 and 31. Connector links 37 at each side have their forward ends journaled on rod 17 and their rear ends coaxially pivoted as at 38 one to each of the rear links 34. The spacing between pivot axis 38 and pivot axis 36 is equal to the spacing between axes 17 and 31. Similarly the spacing between axes 36 and 31 is equal to the spacing between axes 38 and 17.

There is thus a parallel linkage formed under each side of the seat 12 in which the members 30 and 34 and the members 29 and 37 are constantly parallel, as in FIG. 6, regardless of the position of the members about their respective pivots. The links 37 may lie directly under the corresponding support bars 29, as shown, to stop forward swinging of links 34 and 30 or may be spaced therefrom so that the pivot member 38 and rod 17 will engage the members 29 to stop such movement. La any event, the leg frames, seat and connecting linkage will be in the position shown in FIG. 5 when the chair is in erect condition with any load on the seat being transmitted to the leg frames through the linkage and rod 17.

To collapse or fold the chair it is merely necessary to exert upward pressure on the rear edge of seat 12. This causes forward tilting of the entire assembly about the bottom ends of legs 16 and at the same time the linkage will begin to open up, as shown in FIG. 6, with links 30 and 34 swinging upwardly about their respective lower end pivots. As this collapsing movement is continued the leg frames 10 and 11 will be brought to the relatively closed position shown in FIG. 7 with the seat being folded into substantial parallelism with the leg frames. To reconvert the chair to its erect condition pressure is exerted on the rear edge of seat 12 in a downward and rearward direction, reversing the folding operation, and the linkage movement is reversed to spread the leg frames and bring the seat to its horizontal position.

The invention accordingly economically and effectively carries out the aforementioned objectives. It is understood that suitable modifications may be made in the structure as disclosed, provided such modifications come within the spirit and scope of the appended claims. 'Having now therefore fully illustrated and described our in- '3 a vention, what we claim to be new and desire to protect by Letters Patent is:

1. In a folding chair having upright front and rear leg frames pivotally interconnected near-theirupperends ona transverse axis for foreand aft relative collapsing and spreading movement'of the lower portions of the frames, each frame having a pair of transversely spaced leg members extending downwardly-from thepivot axis forrengagement with a chair supporting surface, said front frame legs extending forwardly in their downward extension when the frames are spread, a front and .arear link pivotally interconnected and respectively having their distal ends pivoted to medial points on the front and. rear leg frames to limit spreading movement thereof, said link interpivot being breakable upwardly to allow collapsing movement of the frames, and a flat seat member disposed horizontally between the front legs and over the front link when the frames are spread, and a parallel motion linkage including said front and rear links supporting said seat for movement of the seat upwardly with and parallel to said frontrlink as theframes are collapsed.

2. The subject matter of claim 1 wherein said front and rear link and the parallel motion linkage including the-same are provided between the front and rear legs at each side of the chair.

3. The subject matter of claim 1 wherein the pivot between the'front link and the front leg frame is provided by a horizontal cross bar integrally connecting said two front legs. V 4. In a folding chair, a front leg frame having a pair of transversely spaced legs, a rear leg frame pivoted on a transverse axisto the upper portion ofthe front leg-frame for relative fore and aft spreading and closing movement of the frames about said axis, a fore and aft extending flat seat disposed crosswise between said legs, a first rigid link having one end pivoted to .the seat on a transverse frame with a chair back mounted on the upper portion thereof and with the leg portions of the frame extending downwardly and forwardly from the back to form a pair of front legs for the chair, a horizontal cross bar transversely interconnecting the medial portions of the front legs, a pair of transversely spaced rear leg-s hingedly connected to the back for fore and after swing movement between spread erect and closed collapsed positions relative to the front legs, a flat chair seat disposed between the front legs, and a collapsible means mounting the seat on the cross bar and said rear legs to hold the seat horizontal when the legs are in spread erect position and to swing the rear edge of the seat upwardly to bring the seat :into substantial parallelism with the rear legs as the legs are moved to their closed collapsed position, said collapsible means comprising parallel front and rear pivot links respectively connecting the underside of the seat with the cross bar and a rear leg, and a rigid connecting link extending parallel to the plane of and under the seat and connecting the cross bar with the rear pivot link.

6. In a folding chair, a front leg frame having a pair of transversely spaced legs, a rear leg frame pivoted on a transverse axis to the upper portion of the front leg frame forirelative fore and aft spreading and closing movement of the frames about said axis, a horizontal cross bar transverselyinterconnecting the medial portions of the front frame legs, a fore and aft extending flat seat disposed crosswise between the front frame legs to rest upon the cross bar when the frames are in spread condi- .tion, rear and front links respectively having their rear ends pivoted 'to the rear leg frame and the cross bar and their forward ends respectively pivoted to the rear portion and the front portion of the seat, and said rear link being greater in length than the front link whereby as the frames are moved in a closing direction the entire seat will tilt forwardly and move upwardly toward the frame pivot axis into a position substantially parallel to the rear leg frame.

References Cited in the file of this patent UNITED STATES PATENTS 179,978 'Vaill 'July 18, .1876 1,508,388 Findley Sept. 16, 1924 2,044,473 Geller June 16, 1936 2,580; 178 Kvarnstrom Dec. 25, 1951 2,948,332 Hamilton Aug. 9, 1960 

1. IN A FOLDING CHAIR HAVING UPRIGHT FRONT AND REAR LEG FRAMES PIVOTALLY INTERCONNECTED NEAR THEIR UPPER ENDS ON A TRANSVERSE AXIS FOR FORE AND AFT RELATIVE COLLAPSING AND SPREADING MOVEMENT OF THE LOWER PORTIONS OF THE FRAMES, EACH FRAME HAVING A PAIR OF TRANSVERSELY SPACED LEG MEMBERS EXTENDING DOWNWARDLY FROM THE PIVOT AXIS FOR ENGAGEMENT WITH A CHAIR SUPPORTING SURFACE, SAID FRONT FRAME LEGS EXTENDING FORWARDLY IN THEIR DOWNWARD EXTENSION WHEN THE FRAMES ARE SPREAD, A FRONT AND A REAR LINK PIVOTALLY INTERCONNECTED AND RESPECTIVELY HAVING THEIR DISTAL ENDS PIVOTED TO MEDIAL POINTS ON THE FRONT AND REAR LEG FRAMES TO LIMIT SPREADING MOVEMENT THEREOF, SAID LINK INTERPIVOT BEING BREAKABLE UPWARDLY TO ALLOW COLLAPSING MOVEMENT OF THE FRAMES, AND A FLAT SEAT MEMBER DISPOSED HORIZONTALLY BETWEEN THE FRONT LEGS AND OVER THE FRONT LINK WHEN THE FRAMES ARE SPREAD, AND A PARALLEL MOTION LINKAGE INCLUDING SAID FRONT AND REAR LINKS SUPPORTING SAID SEAT FOR MOVEMENT OF THE SEAT UPWARDLY WITH AND PARALLEL TO SAID FRONT LINK AS THE FRAMES ARE COLLAPSED. 